Five Digit Decimal Counter
I can take next to no credit for this. It is almost identical to Tim Robinson’s which you can find at the following link:
Original decimal counter
The tension springs have been replaced with compression springs. The means the tension on the detent rollers can be adjusted by adding washers. Additionally the cranks do not need the tapped bore at right angles to the arm.
Also included is an alternative advance mechanism. Two semi-circular discs on the main reel are in close contact with bosses on the advance rotor which hold it in position until an arm moves the advance rotor by ¼ of a turn. Meshing a 38 tooth gear to a 95 tooth gear provides a 5:2 ratio to get the final tenth of a turn.
Unfortunately the main reel takes more than a tenth of a turn to advance the rotor which means when the main reel is at 9 the next reel will have partially advanced. I haven’t found a solution to this. Whatever solution is found, it would make for a much more bulky decimal counter.